title: Measurement capability of field portable organic vapor monitoring instruments under different experimental conditions.
abstract: The performance of field portable direct-reading organic vapor monitors (DROVMs) was evaluated under a variety of experimental conditions. Four of the DROVMs had photoionization detectors (ppbRAE, IAQRAE, MultiRAE, and Century Toxic Vapor Analyzer), one had a flame ionization detector (Century Toxic Vapor Analyzer), and one was a single-beam infrared spectrophotometer (SapphIRe). Four of each DROVM (two Century Toxic Vapor Analyzers and SapphIRes) were tested. The DROVMs were evaluated at three temperatures (4 degrees C, 21 degrees C, and 38 degrees C), three relative humidities (30%, 60%, and 90%), and two hexane concentrations (5 ppm and 100 ppm). These conditions were selected to provide a range within the operational parameters of all the instruments. At least four replicate trials were performed across the 18 experimental conditions (3 temperatures x 3 relative humidities x 2 concentrations). To evaluate performance, the 4-hr time-weighted average readings from the DROVMs in a given trial were compared with the average of two charcoal tube concentrations using pairwise comparison. The pairwise comparison criterion was +/-25% measurement agreement between each individual DROVM and the DROVMs as a group and the average charcoal tube concentration. The ppbRAE group performed the best with 40% of all readings meeting the comparison criterion followed by the SapphIRe group at 39%. Among individual DROVMs, the best performer was a SapphIRe, with 57% of its readings meeting the criterion. The data was further analyzed by temperature, humidity, and concentration. The results indicated the performance of some DROVMs may be affected by temperature, humidity, and/or concentration. The ppbRAE group performed best at 21 degrees C with the percentage of readings meeting the criterion increasing to 63%. At the 5 ppm concentration, 44% of the ppbRAE group readings met the criterion, while at 100 ppm, only 35% did. The results indicate that monitors can be used as survey tools. Based on the data, the inconsistent performance of these DROVMs may not allow them to be used for determining compliance with occupational exposure limits.
authors.affiliation: Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505-2888, USA. ccoffey@cdc.gov
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Coffey
authors.forename: Terri A
authors.initials: TA
authors.lastname: Pearce
authors.forename: Robert B
authors.initials: RB
authors.lastname: Lawrence
authors.forename: Judith B
authors.initials: JB
authors.lastname: Hudnall
authors.forename: James E
authors.initials: JE
authors.lastname: Slaven
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Martin
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002138:Calibration; D002606:Charcoal; D004784:Environmental Monitoring / Q000295:instrumentation*; D006586:Hexanes / Q000032:analysis; D006813:Humidity; D013696:Temperature
chemical_list: D000393:Air Pollutants; D006586:Hexanes; D002606:Charcoal